Types of Soil in India is an important topic in Indian Geography. It plays a key role in agriculture, which is the backbone of the country. Questions about soil types often appear in competitive exams like SSC, Railways, State PSC, CDS, and UPSC.
In this blog post, we’ll explore the different Types of Soil in India along with their features, the states where they are found, their agricultural uses, and percentage distribution. You’ll also find helpful PDFs with maps and multiple-choice questions (MCQs) based on past exam papers.
Introduction
- Soil is a mixture of organic matter (humus), minerals, gases, liquids, and microorganisms that support life.
- It is commonly known as the top layer of the Earth’s crust that sustains life.
- The outermost layer of the Earth made up of soil is called the Pedosphere.
- The word “pedon” comes from Greek, meaning “ground” or “earth”.
The Pedosphere interacts with:
- The Lithosphere (Earth’s solid crust and upper mantle),
- The Hydrosphere (water bodies),
- The Atmosphere (air), and
- The Biosphere (living organisms).
Soil has four major functions.
- It provides a medium for plant growth.
- As a means of water storage, supply, and purification
- As a modifier of Earth’s atmosphere
- As a habitat for organisms
What is Soil?
- Soil is the loose material or top layer of mantle rock called regolith, made up of small particles and humus that support plant growth.
- It contains mineral and rock particles, decomposed organic matter, air, water, and living organisms.
Factors influencing soil formation include:
- Parent material
- Relief (landform features)
- Climate
- Vegetation and life forms
- Time
Four main components of soil:
- Inorganic or mineral fractions from parent material
- Organic matter from decayed plants and animals
- Air
- Water
- The process of soil formation is called “pedogenesis”, which occurs under specific natural conditions, with each element of the environment playing a role.
Biotic and Abiotic Factors of Soil
- Soil is a vital component of the ecosystem and consists of both biotic and abiotic factors.
Biotic Factors
- Living components like:
- Various organisms
- Insects
- Plants
- Animals
Abiotic Factors
Non-living components like:
- Minerals
- Water
- Air
- Silicate minerals are the most common in the Earth’s crust, with feldspars being the most abundant silicates.
Soil supplies essential metals for plant growth, including:
- Nitrogen, Potassium, and Phosphorus (primary nutrients).
- Less common minerals like Calcium, Magnesium, and Sulfur (secondary nutrients).
What are the Compositions of Soil?
Five Main Components of Soil:
Mineral Matter
- Derived from the disintegration and decomposition of rocks due to pressure and temperature.
Organic Matter
- Formed from the decay of plant residues, animal remains, and microbial tissues.
Water
- Comes from the atmosphere and various chemical, physical, and microbial reactions in the soil.
Air or Gas
- Sourced from the atmosphere, and results from the activity of roots, microbes, and soil chemicals.
Organisms
- Includes living beings like insects, worms, and microorganisms such as small microbes.
Soil Profile / Horizons
What is a Soil Profile?
- A soil profile is a vertical section of the soil showing its different layers, called horizons, which are arranged parallel to the surface.
- Each horizon has a distinct texture, composition, and function.
Soil Horizons
Horizon A (Topsoil)
- The topmost layer of the soil profile.
- Contains a mix of organic matter, mineral particles, nutrients, and water, making it ideal for plant growth.
- Rich in microorganisms and has the highest organic content.
Horizon B (Subsoil)
- Lies beneath Horizon A and contains more minerals but less organic matter or humus.
- Harder and denser than Horizon A.
- Serves as a transition layer between Horizon A (above) and Horizon C (below).
Horizon C (Parent Material)
- The lowest layer of the soil profile.
- Made up of unconsolidated, partially weathered, or decomposed rock.
- Acts as the source of minerals and nutrients for the upper layers through the process of weathering.
Additional Horizons (if present)
- Horizon R (Rock): The solid bedrock layer beneath Horizon C.
- Horizon O (Organic): A layer rich in organic debris like decomposed leaves and plant matter, typically found in specific soil types.
Importance of Soil Horizons
- These layers play a critical role in the ecosystem’s sustainability by influencing the types of plants and animals that can thrive in the area.
- Soil horizons determine the properties of soil, including its fertility, water retention, and support for vegetation.
Classification of Soil
Ancient Classification (Based on Fertility):
- Urvara: Fertile soil.
- Usara: Sterile or infertile soil.
Classification Based on Texture:
- Sandy Soil
- Clayey Soil
- Silty Soil
- Loamy Soil
Classification Based on Color:
- Red Soil
- Yellow Soil
- Black Soil
Types of Soil in India (As per Indian Standards)
- Based on their nature, genesis, color, composition, and location, Indian soils were classified into eight major groups as per the ICAR survey report.
- In 1953, the Indian Council of Agricultural Research (ICAR) formed the All India Soil Survey Committee.
Classification of Soil
Ancient Classification (Based on Fertility)
- Urvara: Fertile soil that supports plant growth.
- Usara: Sterile or infertile soil with low productivity.
Classification Based on Texture
- Sandy Soil: Loose, well-drained, and poor in nutrients.
- Clayey Soil: Compact, retains water, and is rich in nutrients.
- Silty Soil: Smooth and fertile, with good water retention.
- Loamy Soil: Ideal for agriculture, with a balanced mixture of sand, silt, and clay.
Classification Based on Color
- Red Soil: Rich in iron, commonly found in warm, dry regions.
- Yellow Soil: Formed due to hydrated iron oxides, found in humid regions.
- Black Soil: Also known as Regur soil, ideal for cotton cultivation due to its moisture-retentive properties.
Types of Soil in India with States
Alluvial Soil of India
General Features
- Most Abundant Soil: Alluvial or Alluvium soil is the most widespread soil type in India.
- Crop Growth: Supports uninterrupted crop growth.
- Coverage: Found over 15 lakh sq. km, covering 45.6% of the total area.
- Transported by Rivers: Deposited by rivers and streams, ranging from sandy loam to clay.
- Sand Content: Decreases from west to east.
- Color Variations: From mild gray to ash gray, depending on deposition depth.
- Immature Soil: Alluvial soils are still in the process of development.
- Location near Foothills: In regions like the Bhabar zone near the Shiwalik foothills.
- Most Productive Soil: It supports the widest range of plant growth.
Location
- Found in the Northern Plains, especially the Indo-Gangetic Plain.
- States:
- Punjab (West)
- West Bengal
- Assam
- River Valleys & Deltas:
- Mahanadi
- Godavari
- Krishna
- Cauvery
Composition
- Rich in:
- Potash
- Phosphoric Acid
- Poor in:
- Nitrogen
- Varying in:
- Iron Oxide
- Lime
Two Types of Alluvial Soil
- Khadar (New Alluvium)
- Deposited Annually by floods.
- Composed of fine silt deposits.
- Bhangar (Older Alluvium)
- Older deposits are found away from floodplains.
- More loamy and clayey in areas like the lower Gangetic Plain and Brahmaputra Valley.
Special Varieties
- Coastal Alluvium: Alluvial soil is found in coastal areas.
- Deltic Alluvium: Found in the delta regions of various rivers.
Suitable Crops
- Leguminous Crops
- Cereals: Rice, Wheat, Maize.
- Sugarcane
- Pulses
- Oilseeds
- Fruits & Vegetables
Key Difference Between Bangar and Khadar
Characteristic | Bangar Soil | Khadar Soil |
---|---|---|
Location | Higher terraces of river valleys | Low-lying areas near riverbanks |
Formation | Older, formed over a longer time | Younger, formed by annual flooding |
Proximity to Rivers | Further from the river | Closer to the riverbanks |
Fertility | Lower fertility due to aging | Higher fertility due to fresh silt and nutrients from flooding |
Soil Texture | Coarser and less fine | Finer and more silty |
Depth | Deeper soil layers | Shallower soil layers |
Drainage | Better drainage | Poorer drainage |
Black Soil of India
General Features
- Alternate Name: Known as ‘Regur Soil’ or ‘Black Cotton Soil’.
- Moisture Retention: Highly moisture-retentive.
- Texture: Swells and becomes sticky when wet and shrinks when dried.
- Cracks in Dry Season: Develops wide cracks during the dry season.
- Self-plowing Soil: Often called self-plowed soil due to its ability to break up on its own.
- Moisture Retention: Retains moisture for a long time, making it crucial for rain-fed crops.
- Coloration: Varies from deep black to gray.
- Percentage Coverage in India: Covers 18.5% of India.
Area Covered
- Main Location: Covers much of the Deccan Plateau.
- States:
- Maharashtra
- Madhya Pradesh
- Gujarat
- Andhra Pradesh
- Some parts of Tamil Nadu
- Rivers: Upper reaches of the Godavari and Krishna.
Composition
- Rich in:
- Lime
- Iron
- Magnesia
- Alumina
- Potash
- Poor in:
- Phosphorus
- Nitrogen
- Organic Matter
Suitable Crops
- Sunflower
- Cotton
- Tobacco
- Castor
- Wheat
- Jowar
- Millet
Types of Soils in India Map
Red and Yellow Soil of India
General Features
- Origin: Developed on crystalline igneous rocks.
- Color: Reddish due to the presence of iron oxide; appears yellow when in a hydrated form.
- Fertility:
- Fine-grained red and yellow soils are generally fertile.
- Coarse-grained soils in dry upland areas are poor in fertility.
Area Covered
- Location:
- Eastern and southern parts of the Deccan Plateau.
- Along the Piedmont zone of the Western Ghats.
- Parts of Odisha and Chhattisgarh.
- Southern parts of the middle Ganga plain.
Composition
- Poor in:
- Lime
- Nitrogen
- Humus
- Phosphorus
- Rich in:
- Potash
Suitable Crops
- Millet
- Cotton
- Wheat
- Rice
- Pulse
- Tobacco
Laterite Soil
Common Features
- Derived from the Latin word ‘Later’, meaning brick.
- Durability: Indefinitely durable, develops in areas with high temperatures and high rainfall.
- Leaching: Result of intense leaching due to tropical rains, where lime and silica are leached away.
- Fertility: Due to intense leaching, laterite soils are generally low in fertility.
- Uses: Widely used as bricks for building houses.
- Weathering: Laterite soil is the end-product of weathering and cannot weather much further.
- Percentage in India: 2.62% of the total soil.
Area Covered
- Tamil Nadu
- Andhra Pradesh
- Kerala
Composition
- Rich in:
- Iron oxide
- Potash
- Aluminum compounds
- Poor in:
- Organic matter
- Nitrogen
- Phosphate
Suitable Crops
- Millet
- Cashew nut
- Tea
- Coffee
- Coconut
- Rubber
- Cinchona
- Cotton
- Wheat
- Rice
- Pulse
- Tobacco
Forest and Mountain Soil
Common Features
- Total Area Covered: 2.85 lakh sq. km (8.67% of India’s total land area).
- Formation: Formed in forested regions where sufficient rainfall is available.
- Texture:
- Loamy and silty on valley sides.
- Coarse-grained on the upper slopes.
- Fertility: The soil found in the lower valleys is fertile.
Area Covered
- Mainly found on the hill slopes of:
- Jammu & Kashmir
- Himachal Pradesh
- Uttarakhand
- Karnataka
- Tamil Nadu
Composition
- Rich in:
- Humus
- Poor in:
- Potash
- Phosphorus
- Lime
Suitable Crops
- Tropical fruits (mainly in Karnataka, Tamil Nadu, and Kerala)
- Tea
- Coffee
- Spices
Arid and Desert Soils of India
Common Features
- Total Area Covered: 4.32% (1.42 lakh sq km)
- Color: Red to brown.
- Texture: Generally sandy in structure.
- Nature: Saline.
- Characteristics:
- Due to the dry climate, high temperatures, and accelerated evaporation, these soils lack moisture and humus.
- Occur in arid and semi-arid regions, as well as waterlogged and swampy areas.
Area Covered
- Found primarily in:
- Rajasthan
- Gujarat (especially the Rann of Kutch)
- Adjoining areas of Punjab and Haryana, particularly between the Indus and Aravalis.
Composition
- Poor in:
- Humus
- Nitrogen
- Rich in:
- Calcium salts
- Phosphate
Suitable Crops
- Pulses
- Barley
- Rape
- Cotton
- Wheat
- Millets
- Maize
Saline and Alkaline Soils
Common Features
- Known as Usara soils.
- Do not support vegetative growth due to high salt content.
- High salt content due to the dry climate and poor drainage.
- Known by different regional names such as:
- Reh, Kallar, Usar, Thur, Rakar, Karl, and Chopan.
Note:
- Excessive irrigation in dry climatic conditions leads to capillary action, which results in salt deposition on the soil’s top layer.
- In areas like Punjab and Haryana, gypsum is added to solve salinity issues.
Area Covered
- Andhra Pradesh, Telangana, and Karnataka.
- Drier parts of Bihar, Uttar Pradesh, Haryana, Punjab, Rajasthan, and Maharashtra.
Composition
- Rich in:
- Sodium, Potassium, and Magnesium.
- Poor in:
- Nitrogen and Calcium.
Suitable Crops
Barley, Oat, Grain sorghum, Sugar beets, Bermuda grass, Tall wheat grass.
Salt-tolerant crops:
Peaty and Marshy Soils
Common Features
- Origin in areas with heavy rainfall and high humidity.
- Supports good plant growth due to its rich organic content.
- Contains huge quantities of dead organic matter.
- Offers rich humus and organic content, with organic matter up to 40-50%.
- Typically heavy and deep black in color.
- In Kerala, peaty soil is known as Kari and is found in the Kottayam and Alappuzha districts.
Area Covered
- Northern Bihar
- Southern Uttarakhand
- Coastal areas of West Bengal, Odisha, and Tamil Nadu.
Composition
- Rich in:
- Organic Matter
- Poor in:
- Potash and Phosphate
Suitable Crops
- Primarily suitable for Paddy Cultivation.
Soil Erosion
What is Soil Erosion?
- This phenomenon can result from natural forces (like wind, water, or glaciers) or human activities (such as deforestation, agriculture, or construction).
- Soil erosion is the process where the topsoil is removed from the land.
- Normally, soil formation and erosive forces work in harmony to maintain a balance between soil creation and loss.
- However, when this balance is disrupted, soil is removed at a faster rate than it can be formed, leading to soil erosion.
Causes of Soil Erosion
- Soil erosion can be caused by both natural and human factors. Here are the common causes:
Natural Factors
- Rainfall Intensity and Amount: High-intensity rainfall can wash away the topsoil, leading to erosion.
- Climate Change: Climate change intensifies extreme weather events like heavy rainfall and floods, which increase soil erosion.
- Wind: Strong winds can blow away topsoil, especially in dry areas or where the soil is bare.
- Water Bodies: Rivers, lakes, and oceans can erode soil along their banks and shores due to wave action and water movement.
- Geological Factors: Rock types and the soil’s parent material affect how prone the soil is to erosion.
- Topography: Steep slopes and hills are more prone to erosion because gravity and water easily move soil downhill.
- Soil Structure: The soil’s texture, organic matter, and drainage capacity influence how resistant it is to erosion.
- Soil Composition: The type of soil (sand, clay, or loam) affects its susceptibility to erosion.
Human Factors
- Deforestation: Removing trees exposes soil to the elements and disrupts the roots that normally hold the soil in place.
- Agriculture: Practices like tilling, monoculture, and overgrazing leave the soil exposed and vulnerable to erosion.
- Construction: Infrastructure development, such as roads and buildings, removes vegetation and disturbs the soil, leading to erosion.
- Mining: Mining activities remove vegetation, change the topography, and expose the soil, causing erosion.
- Poor Land Management: Lack of proper erosion control measures, or not maintaining buffer zones between fields and water bodies, can contribute to soil erosion.
- Soil Compaction: Heavy machinery or excessive foot traffic can compact the soil, reducing its ability to absorb water and making it more prone to erosion.
- Improper Irrigation: Incorrect irrigation practices can lead to runoff, rather than water soaking into the soil, which causes soil erosion.
How to Prevent Soil Erosion
Several effective measures can be taken to prevent soil erosion. Here are some of the most common ways:
1. More Plant Cover
- Planting vegetation like trees, shrubs, and ground cover helps anchor the soil with their roots. The plants also intercept rainwater before it hits the soil, reducing the risk of erosion.
2. Use of Mulching
- Mulching involves covering the soil with organic material like leaves or straw. This layer protects the soil from erosion, improves fertility as it decomposes, and helps retain moisture by reducing water loss.
3. No-Till Farming
- In no-till farming, crops are planted without disturbing the soil, which reduces erosion by leaving the soil intact. This method also promotes the growth of organic matter that improves soil health.
4. Contour Farming
- Contour farming involves planting crops along the contours of the land. This technique slows the flow of water, reduces soil erosion, and helps retain water on the land.
5. Terracing
- Terracing involves building steps into steep slopes to reduce erosion. These terraces create level areas that trap water, reducing its speed and preventing soil loss.
6. Soil Conservation Practices
- Practices like crop rotation, reduced tillage, and crop residue management help maintain soil health and reduce soil erosion by preventing the soil from becoming exposed and vulnerable.
7. Cover Crops
- Cover crops are planted between cash crops to protect the soil. They improve soil fertility and prevent erosion by keeping the soil covered and promoting root growth.
8. Soil Stabilization Measures
- In areas prone to erosion, soil stabilization measures such as retaining walls, ripraps, or gabion baskets can be used to secure the soil and prevent further erosion.
By implementing these measures, soil erosion can be minimized, helping to preserve soil fertility and prevent land degradation.
Different Types of Soil Chart
Soil Name | Location | Rich in | Deficient In |
---|---|---|---|
Alluvial Soil | Indo-Gangetic Plain, River Valleys | Potash | Nitrogen |
Black Soil | Deccan Plateau [Maharashtra, Madhya Pradesh, Telangana, Andhra Pradesh, Gujarat, Parts of Tamil Nadu] | Lime, iron, magnesia and alumina. potash | Phosphorous, nitrogen and organic matter |
Red and Yellow Soil | Tamil Nadu, Parts of Karnataka, West Bengal (Bankura, Birbhum) | Iron Oxide | Nitrogen, Phosphorous, and Humus. |
Laterite soils | Karnataka, Kerala, Tamil Nadu, Madhya Pradesh, | Iron Oxide, Potash | Organic matter, Nitrogen, Phosphate and Calcium |
Forest and Mountain Soils | Forest area of Tamil Nadu, Kerala Jammu & Kashmir, Himachal Pradesh Uttarakhand | Humus | Potash, Phosphorus, Lime |
Arid and Desert Soil | Rajasthan and adjoining areas of Punjab and Haryana Rann of Kutch | Soluble Slats, Alkaline, Calcium Carbonate | Organic Matter |
Saline Soil | Gujarat, Uttar Pradesh Maharashtra, West Bengal and Rajasthan | Salt of Calcium, Magnesium sulfurous acid and Sodium | Humus, Nitrogen |
Types of Questions Asked in Competitive Exams
Here are some key areas in this topic that are important for every competitive exam. Most questions on this topic are asked from these key areas.
- Percentage of soil groups (to arrange soils by availability)
- Composition of soils (rich and poor in minerals)
- Nicknames of major soil groups (e.g., regur soil, also known as black soil)
- Nicknames of specific soil groups (e.g., reh, kallar, and usar, all nicknames for saline and alkaline soils)
- Specific characteristics of soil groups (e.g., laterite soil is the end product of weathering and cannot be weathered further)
- Specific agricultural products associated with particular soils (e.g., cotton grown well in black soil)
Conclusion
This overview of the different types of soil in India is essential for anyone preparing for competitive exams related to Indian geography. By understanding each soil type’s characteristics, distribution, and agricultural significance, you will be better equipped to answer questions on this topic in your exams.
FAQs
Answer: List of the 8 major soil groups notified by ICAR
• Alluvial soils
• Black soils
• Red soils
• Laterite soils
• Forest and Mountain soils
• Arid and Desert soils
• Saline and Alkaline soils
• Marshy and Peaty soils
Answer: Alluvial soils are mainly found in India. It occupied an area of 45%.
Answer: The Alluvia soil is the largest soil group in India.
Answer: Alluvial soil is best due to its high fertility. It contains enough organic matter like Humus, which supports easy plant growth.
Answer: Alluvial Soil
Answer: As per ICAR the major types of soil in India are” Alluvial soils, Black soils, Red soils, Laterite soils, Forest and Mountain soils, Arid and Desert soils, Saline and Alkaline soils, and Marshy and Peaty soils”.
Answer: The Deccan plateau is mostly covered by Black or regur soil. Some part of the southern part of the Deccan plateau is covered by red soil. This red soil covers Almost all of the Tamil Nadu area. The Black soil is suitable for the cultivation of Cotton.
Answer: Two Types of Alluvial soil are found in India. These are Khaddar and Bhangar. Khaddar is the new alluvium soil formed by the deposition of fine silts and Bhangar is the old alluvial soil formed away from the floodplains.
Answer: Laterite soil is found in the southern part of the Deccan plateau, in places like Kerala, Tami Nadu, and Andhra Pradesh. The Laterite soil is suitable for the cultivation of cashew nuts.
Answer: Pedology is the subject that deals with the study of soil.